1. Field
The disclosure relates to output of a constant voltage, and more particularly, it relates to a constant voltage circuit, a constant voltage supply system and a constant voltage supply method in which a transient fluctuation in voltage caused by a fluctuation in the input voltage is suppressed.
2. Description of Related Art
With the development of integrated circuit technology, progresses are made in the miniaturization of circuit elements constituting highly integrated circuits such as SOC, which have a plurality of functions mounted onto one chip. In this context, withstand voltage restrictions of circuit elements require lower applied voltage. These restrictions also require that no transient overshoots of a voltage value occur and that a voltage having a stable value is outputted to thereby ensure a high-speed operation. Generally, this applied voltage is obtained by converting an external supply voltage which is supplied from exterior into an internal voltage having a stable constant voltage value, and is then supplied.
Such a related technology is disclosed in “CMOS Analog Circuit Design”, by Phillip E. Allen and Douglas R. Holberg, (US), Second Edition, Oxford UNIVERSITY PRESS, 2002, p. 425.